When a pipe is to be joined to a fitting having an internal shoulder it is common for the free end of the pipe to be inserted into the fitting to an extent sufficient to enable the end of the pipe to abut the shoulder. The pipe and fitting may not be welded together in such relative positions, however, because of the likelihood that the weld will crack or break due to thermal expansion and contraction of the pipe and fitting. Accordingly, it is the practice to provide a clearance between the free end of the pipe and the shoulder of the fitting, such clearance amounting to at least 1/16 inch according to most welding standards. If welds are to comply with such standards it is essential that the welder have some means of ensuring that the spacing between the shoulder of the fitting and the end of the pipe is not less than the minimum prior to and during welding of the pipe and fitting. To attain this objective welders heretofore have utilized many techniques with varying degrees of success. One technique is disclosed in U.S. Pat. No. 3,973,765 which makes use of a jig in which the fitting and the pipe are positioned prior to and during welding. Another technique heretofore employed utilizes a tool having a pair of clamping jaws between which a pipe to be welded to a fitting may be gripped. Associated with such jaws are a pair of pivoted fingers which may be swung to a position in which they are interposed between the associated clamp jaw and the free end of the fitting. In this construction, however, interference between the blade and the pipe could be encountered during movement of the fingers into their spacing position. Moreover, the fingers are exposed to the likelihood of being bent. Further, such tool is unable to accommodate pipes of significantly different diameters.